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When I took apart my center console I took this picture of the vacuum hose arrangement on the back of the unit. Now I can't tell which black is which and it seems there should be four hoses? Any thoughts?
To me it looks like a replacement valve only because I see no numbers near the ports.
You can use this photo to connect the dots of what you have and don't have.
Last edited by bmotojoe; Nov 23, 2020 at 06:28 AM.
What I can confirm side by side with a new AcDelco switch:
Port #1 Missing Vacuum Supply Line
Port #2 This should be open as it is the systems exhaust port
Port #5 Black/Green stripe hose correct port landing
Thanks all. I’ve looked so many different diagrams and pictures it seems they all tell Dan different story. But what I gather here so far is that:
1. Needs to a hose - what color though?
2 shouldn’t have a cap on it but be open
3. Needs to be traced
4. Needs to be traced
5. I have n the right place.
Thanks all. I’ve looked so many different diagrams and pictures it seems they all tell Dan different story. But what I gather here so far is that:
1. Needs to a hose - what color though?
2 shouldn’t have a cap on it but be open
3. Needs to be traced
4. Needs to be traced
5. I have n the right place.
oh, and my 79 has a/c
Many thanks!
reread excellent post above.. it tells you what goes where.. and the green.. trace cack your others.. one is your vacuum supply.. then deduction the rest.
again get the aim .. i got mine from Willcox..and all my tach stuff.. and his tutorials are excellent.. visit the site..
Last edited by interpon; Nov 23, 2020 at 09:48 AM.
Got it. Thanks for redirecting me. I get lost sometimes and frustrated. Comes with my ptsd. Makes it tough to get through things like this, but you all are sure helping. Many thanks.
Just for a test, pull lines 3 & 4 from the vacuum valve and start engine.
One of them (or both ie. tee to Hot water shutoff vacuum valve) could be your vacuum supply source.
If you find one of them is the vacuum source connect that hose to port #1 of the vacuum valve.
Cap off #4 leaving port #2 open.
Connect, or leave the other hose (3 or 4) to port #3
This should give you switched vacuum for all EXCEPT the A/C air valve.
Last edited by bmotojoe; Nov 23, 2020 at 10:36 AM.
Print out the diagram interpon posted from Willcox Corvette.
In my photo the yellow circle (small black hose) is the same hose marked TO SOURCE on the drawing.
One side of the metal splitter check valve (Red Circle) is for your headlight vacuum circuit and the other is your HVAC circuit.
This photo is from a 77, sure your 79 is somewhat the same.
That's all I got....
Thanks Interpon. That last forum link was a huge help. Thanks for all your assistance. I’m sure I’ll get it fixed now. Couldn’t have done it without you👍
AC vacuum confusion
